Shipwrecks, maritime archaeology and antique pottery and porcelain from the South China Sea

THE VALUE OF SHIPWRECKS, MARINE ARCHEOLOGY AND RELATED ANTIQUE POTTERY

Shipwrecks which remain undisturbed on the seabed for centuries provide vital information about the past. The challenge of archeology is to understand the past by studying material traces. On land, archaeologists may excavate burial sites, lost monuments or deposited waste. At sea, marine archaeologists may excavate ships fully loaded with today's antique pottery. Object on board are usually assumed to be contemporary products dating from the year of sinking. Antique pottery recovered from such dated assemblages in the South China Sea, yield important clues about Asia's ceramics developments and associated maritime trade

"As time capsules, each with content deposited at a single moment in time, these are more valid as dating evidence than are decades of scholarly guesswork based on unprovenanced museum collections"

(Asian Ceramic Research Organization)

The European East India ships of

the 17th century provided the first direct contact with Asia's spices,

silk and ceramics.

The Asian's had a well developed trading system already by the 9th century. Pottery at that time was based on old tradtions.

Six centuy old underglaze black decorations

from the Turiang shipwreck

The advantages with one company, one objective and archeology approach is maybe best seen in the below collection of ceramics. These pieces are all from the Sisatchanalai kilns but found on four different shipwrecks. These antique pottery, as will be seen, clearly shows the technical and stylistic developments at those kilns. This type of comparisons has not been done earlier, simply because not one organisation had access to all the materials necessary for such comparison. For more information about the different shipwrecks, cargo and respective dates, please refer to below links.

Another Southeast Asian built vessel loaded with the finest of all celadons from the Sisatchanalai kilns

Historical shipwrecks with cargoes of porcelain and pottery are perfect time capsules if properly excavated and researched. Frozen in time, shipwrecks provide an accurate insight into ancient maritime trade and the goods traded at the time when the ship was lost. From the ten shipwreck excavated and researched by Nanhai Marine Archaeology, we have learned a lot about this trade and been able to assign estimated dates to these ten shipwrecks and thereby date the artefacts we recover. We have learned about different shipbuilding designs, construction methods and been able to map shipbuilding sites and learned how they changed over time, due to political events.

To read more about the Shipwrecks, marine archeology, old time pottery and antique pottery click on its respective link:

Nanhai Marine Archaeology Sdn. Bhd. was incorporated on the recommendation of the Malaysian authorities. This was done in order to formalize and to expand on the company’s researcher’s extensive knowledge of Asia’s ceramic developments and maritime trade.

The company’s researchers have been engaged in the search for historical shipwrecks for more than two decades and another decade researching maritime trade. Most of this work is concentrated to the South China Sea, a virtual highway for ancient shipping linking China to India, the Middle East and Southeast Asia in an extensive maritime trade system. This ancient trade started sometime around the 4th century and lasted well into the 19th century.

Following a successful shipwreck discovery, the company obtain a government permit to excavate the wreckage, and then carry out detailed marine archaeological procedures in recovering the artifacts, mapping the ship's remains and securing other data for future research. After each concluded project and following conservation of recovered artifacts, we search for and pinpoint ruined kiln sites and compare its wasters with the recovered ceramics until we are satisfied we located the place in which the shipwreck pottery was made centuries earlier.

Our arrangement with the Malaysian authorities is such that we finance all operations and train young Malaysian nationals (on our initiative) in maritime archaeology and related research. After giving all unique and single artifacts and thirty percent of all recovered items to the National Museum (and assisting with exhibitions of artifacts from each project) we are allowed to sell our portion of the recovery to finance future projects. The findings from ongoing research and the compilation of reports, books and catalogues are available on these pages as well as on a separate Internet site: http://www.maritimeasia.ws

Due to the unquestionable authenticity and precisely dated shipwreck pottery, many International Museums now display our shipwreck pieces as reference material.

The artifacts sold on this website are therefore legally and properly excavated and can be supplied with an export permit from the Department of Museum in Malaysia should this be required. This unique working arrangement makes us one of the few Internet sellers that sell from own excavation and issues a meaningful Certificate of Authenticity with all artifacts with a serial number.

So, if you are interested to purchase some of our Antique porcelain, old time pottery or other shipwreck artifacts from the Song dynasty, Ming porcelain or Chinese blue and white porcelain or the famous Yixing teapots, you can rest assured that every piece is excavated through proper archaeology by our own staff. We do not sell anything that is not excavated by ourselves or properly recorded and researched before offered for sale so every piece comes with the “Best possible provenance”

WE ENCOURAGE YOU TO EMAIL OUR PRINCIPAL RESEARCHER; Sten Sjostrand SHOULD YOU HAVE ANY QUESTIONS ABOUT YOUR POSSIBLE PURCHASE

From the shipwrecks presented here, and the archeology made, we have established how the early Chinese monopoly on ceramic export was challenged in the 14th - 16th century by two rivaling Thai kiln complexes, each making different types of traditional Chinese pottery. It also becomes clear that the Chinese regained its monopoly in the 17th century when the Europeans entered into the Asian trade network

Dreary weather and intermittent rain has led to a dramatic drop in temperature over the last few days and then, just as the rain finally stopped, a cold wind began to blow from the north. It whipped up high waves and enormous swells that broke repeatedly against the side of the ship giving the deck, and everyone on it, a good showering. It was unbearably cold, wet and miserable.

Captain Heng Tai dexterously managed to avoid getting any salt water in his face as he crouched and turned with every hit. He was an experienced captain who had sailed this route many times before, but never so late in the season. The best time for the voyage was December when the northeast monsoon winds guaranteed a fair and safe passage all the way down the South China Sea. But now, late in February, the winds were forceful, occasionally violent and sometimes frightening. The swell generated by these waves was higher than any Heng Tai could remember.

As well as being cold and wet, Heng Tai was now starting to get a very uncomfortable feeling in the pit of his stomach. The junk he commanded was old and hadn’t been reinforced against the hungry attacks of the Teredo woodworms, which feasted on vessels like this. The owner had recently lost a ship near the Malaysian islands and didn’t have sufficient reserves to pay for the sacrificial planks that would protect the hull from the woodworms’ greedy onslaught. It was this cost-cutting that now worried Heng Tai and he bitterly regretted the time he’d had to spend waiting to load the cargo in Ayutthaya. Without that delay he would have been at sea much earlier and none of this would be happening.

Ever since the ‘‘Ming ban’’ when emperor Hongwu imposed restrictions on private overseas trade, potters at the Thai kiln sites had been working flat out to meet the growth in demand from the Southeast Asian market. They were now supplying more than half of the total ceramics for the whole region and the increase in orders meant the kilns were swamped and finding it increasingly hard to meet delivery deadlines. Merchants and captains, like Heng Tai, were seriously concerned about these delays; after all, the monsoon waits for no man.

Heng Tai had docked in Ayutthaya in December and had waited patiently for two months before his main cargo finally arrived from the ceramic kilns up north. He’d already loaded more than 20 tonnes of iron ore and ingots and was worried about the uneven distribution of his cargo, so he was greatly relieved when, at last, the celadon ware was loaded and the junk was well balanced again. The last water containers were filled and the chickens and ducks, which would feed the crew during the voyage, were secured. Heng Tai was finally able to head downriver into the Bay of Siam, where he set his sails and laid a course for Terengganu.

In those days this part of the Malaysian east coast was under the suzerainty of the Kingdom of Ayutthaya, so the waters off Terengganu were safe and familiar and Heng Tai could proceed without danger. When Heng Tai sighted the islands off Terengganu he set a new course for Tioman Island further down the coast. Tioman was a regular stopover point for sailors from all over Asia as it provided good navigational references and had a plentiful supply of fresh water. For many centuries seafarers had stopped there to offer prayers for a safe voyage and trade for some local fruit before continuing their arduous journey. Here Heng Tai would replenish his fresh water supply before setting sail for Java, his final destination.

Normally the stretch between Terengganu and Tioman was an opportunity for the captain and navigator to relax for a while. There was a straight deepwater trench all the way so it was usually plain sailing. This was a well-used shipping lane and he was hoping to come across a Chinese junk, sailing in spite of the ‘‘Ming ban’’, which he could hail for the latest news from China. But on this cold February afternoon, the strong winds and towering waves had ruled out any possibility of such communication and as Heng Tai fought to keep control of his ship his thoughts wandered homewards.

Heng Tai’s father had been an experienced sea captain who had left China fifty years before, shortly after the ‘‘Ming ban’’ came into force. With their livelihoods at stake many seafarers like Heng Tai’s father, as well as merchants and artisans, had fled to Thailand where they were able to continue their trade. It was these people who had made the celadon ware he was now carrying.

The Javanese kingdom of Majapahit, towards which he was heading, was flourishing and attracted many foreign merchants from all over Asia and the Middle East who paid top price for celadon ware as they believed it had magical protective powers. Heng Tai was a good trader and knew the buyers well he also knew this year’s celadon was the best quality to ever come out of the Sisatchanalai kilns in northern Siam so he was sure of making a handsome profit. Hopefully then his ship could be reinforced.

Heng Tai’s attention was suddenly drawn away from thoughts of future profit and ship maintenance as the wind continued to increase. Sea conditions were getting worse by the minute putting untold strain on the vessel and his nerves as he worried about the safety of his ship, crew and the precious cargo. However, Heng Tai’s anxiety was nothing compared to how one of the passengers, a young man called Phra Dharmaraja, was feeling.

Dharmaraja was the king of Siam’s envoy who had boarded the ship in Ayutthaya.

Everyone could tell just by looking at him that he wasn’t a sailor. As a child he’d been traumatised by a crossing of the Chao Phraya River and had kept away from boats ever since. Now, here he was being tossed about in middle of the South China Sea living out his worst nightmare. He was the proud and only son of the first ‘Phra Khlang’ - the minister in charge of Ayutthaya’s treasure. His father’s position had allowed him to pull enough strings to secure a well-paid job in the revenue department and a recent promotion had further increased his confidence and status. It was a rare thing for a civil servant to be summoned by the king, so he’d been surprised and honoured when he was called to the palace. The king appointed Dharmaraja as his personal envoy and commanded he accompany Heng Tai to Java to deliver some gifts to the king of Majapahit in reciprocation for the tributes the Majapahit ruler had earlier sent to Ayutthaya. Now as he clung to the handrail for dear life he wondered, between bouts of nausea and waves of terror, whether he’d be able to complete the mission he had been entrusted to undertake.

Every wave was forcing the ship into a near broach; even a small shift in the heavy cargo could prove disastrous. The crew had managed to lower some of the sails to reduce the strain on the hull and rigging and were now struggling to take down the remaining sails, which were glued, by the force of the wind, to the mast, yarn and rigging. Heng Tai and his crew knew that if the sails remained aloft they would eventually overpower the vessel but there was nothing more they could do.

With his proud character reduced to a mere memory and, in spite of being seriously concerned about his own safety and comfort, Dharmaraja had not forgotten the importance of his mission. He knew that if he failed to deliver the gifts to the Majapahit ruler, it might cause some diplomatic tension and it would certainly embarrass his father.

The most important of all the gifts he was bearing was a royal seal, which reaffirmed Ayutthaya’s friendship and military alliance. He kept it in a silk pouch tied around his waist, which he checked from time to time to make sure that it was still secure. Arriving without the seal would mean landing without any purpose. He resolved that, no matter how sick and frightened he was, he would not let this happen.

Suddenly, the crates containing the chickens and ducks were picked up by a huge wave and thrown onto the deck with such force that they smashed to pieces flinging the traumatised animals all over the place. As he listened to their terrified honks and screeches a premonition of impending doom sent an icy chill down Dharmaraja’s spine.

The tiller and rudder were under enormous and constant pressure as Heng Tai battled the raging storm to keep the ship on course. Then, just as night fell, the strain finally took its toll and the tiller broke. There was nothing more to be done. Without the ability to steer her, the ship remained parallel to the waves and the sails dragged the vessel down sideways. In a last effort to save the ship, the crew tried to slash the sails but it was too late. Capsizing was imminent as water came crashing over the decks from all directions. Heng Tai’s last effort of beaching the ship on the shores of Tioman Island had proved impossible. The struggle to stay afloat was over.

Dharmaraja tried to save himself by clinging to the main mast in the hope of climbing to safety from the water that now engulfed him. Being more experienced in this kind of situation, Heng Tai and his crew scoured the sea for some floating debris to cling to and slowly drifted away from the rattling sails, away from the creaks and groans of the straining hull, away from Dharmaraja’s screams. The ship was swallowed up, leaving nothing but darkness and silence in its wake.

Epilogue

Almost 600 years later, a lone Swedish diver, monitored by an advanced ROV (remote operated vehicle) descended on the very spot where the vessel sank The only visible remains of the once proud ship was a mound of broken and overgrown ceramics. There was no sign of any ship’s timber above the seabed, the Teredo woodworms had taken care of that long ago.

The mound still points towards Tioman Island but the distance is too far for Heng Tai and his crew to have reached it safely in those sea conditions. Dharmaraja would not have survived by clinging to the mast top either as the water was too deep, but the relationship between Ayutthaya and Majapahit did survive, even without the royal gifts.

Although fictitious, everything in Heng Tai’s story is based on evidence uncovered during the excavation of the Royal Nanhai shipwreck. A seal was found next to the mast step but no remains of Dharmaraja could be found.

Early Arab and Indian explorers opened the earliest maritime trade route between China, India and the Middle East. By the 8th century Chinese merchants joined the trade and it wasn’t long before the South China Sea became a bustling marine highway.

Ships laden with Chinese pottery, textiles and iron stopped and trade all along the route, returning with cargoes of exotic indigenous products regarded as luxury items in China. By the 13th century, green glazed celadon ware was in big demand as its colour resembled jade. It also had a reputation for having magical powers; Marco Polo was once told that celadon emitted a ringing tone when danger approached its owner. It was also reputed to change colour if poisoned food was placed on it. No wonder everyone wanted this ware, it was the only kind of life assurance available in those days. But whether celadon was really magical, or its “special powers” were nothing more than an innovative marketing strategy, the reality was that sales soared. As a result Chinese ware enjoyed a virtual monopoly in the ceramics trade until the late 14th century.

As maritime trade increased, the Yuan dynasty slipped deeper into decline and eventually fell in 1368 to Zhu Yuan Zhang, a Chinese peasant who had led a successful rebellion against the Mongols. He set up court in Nanjing where he established the Ming dynasty and named himself Hongwu, the ‘Son of Heaven’. Hongwu was eager to restore Chinese culture and so he reintroduced Confucian ideology that ranked chivalry higher than profit. Confucian scholars were given key positions at court but had little interest in seeing China develop into a great maritime trading power. Instead they concentrated on developing internal trade by rebuilding the network of canals that had been destroyed during the Mongol dynasty. Hongwu felt threatened by the wealthy merchants and forcefully moved many of them inland. He then ordered their ships to be destroyed and prohibited all private overseas trade and the building of ocean going vessels. This ‘‘Ming ban’’ on overseas private trade was introduced in 1371 and was often heavily enforced. Anyone caught smuggling paid with his life.

By the beginning of the15th century however, a new ruler, the Yongle emperor (1403-1324) sent admiral Zheng He (also known as Cheng Ho) on a series of famous ocean voyages to promote tributary trade. This kind of trade emphasised the giving and receiving of tribute, which was in harmony with Confucian principles and meant trade could continue in the name of the emperor. The expeditions visited Java, India, Mogadishu on the coast of Africa, Hormuz on the Persian Gulf, and sailed up the Red Sea to Jeddah. Gifts were exchanged, and rare spices, plants and animals, including a giraffe, were sent back to China.

The ‘‘Ming ban’’ caused China to loose its monopoly of the ceramic trade forcing many Chinese potters to migrate. During the 14th century, ceramic production in Thailand and Vietnam increased and the Thai ceramic industry became internationally famous. The main developments seem to have been at the Thai kilns of Sukhothai and Sisatchanalai, which flourished between the 14th and 16th centuries. The kilns at Sukhothai produced underglaze black ware, which was very similar in design and decoration to pots that had been made in the northern Chinese kilns of Cizhou centuries earlier. The kilns at Sisatchanalai made celadon, which began appearing in overseas marketplaces from the last quarter of the 14th century

Evidence from 14th to 16th century South China Sea shipwrecks supports the idea that the Chinese shipbuilders also moved to S.E. Asia. Traditionally, Chinese ships were made from a temperate climate species of wood and constructed around transverse bulkheads that were held together by square iron nails. In contrast, Southeast Asian vessels were made from tropical hardwood and built around a framework joined by wooden dowels; a technique still used by boat builders in Terengganu today. Almost all the shipwrecks from this period had transverse bulkheads attached to a framework, joined by wooden dowels and built from tropical hardwood. These hybrids are commonly referred to as South China Sea vessels and provide evidence that Chinese shipbuilders migrated southwards.

The ‘‘Ming ban’’ was officially abolished in 1567 and this allowed the Portuguese to openly trade with China. By now Chinese potters were crafting exquisite blue and white porcelain ware that was as translucent as jade and almost as precious. It captivated an ever-increasing group of European buyers and by the beginning of the 17th century blue and white porcelain was being exported to Portugal, Holland and England. From the beginning of the 18th century, more and more European merchant vessels were crossing the South China Sea with thousands of pieces of blue and white porcelain onboard. Many private European traders settled in Asia, using locally built ships to join in this lucrative commerce.

The ten historical South China Sea shipwrecks presented in this web page span these centuries of change. Before the discovery of these wrecks, most of the information available to ceramic collectors came from pots that had been found at various archaeological excavations on land. These became a sort of benchmark for art historians who tended to date all types of similar ceramic pieces according to the dates of these sites. Finding the ten shipwrecks not only resolved many of the questions I had about dating my own collection, it also provided important evidence for past maritime trade, ceramic development and shipbuilding techniques during a time when Asia was the leading technological hub and a dominant force in global trade.

Diving on any shipwreck is an exciting experience full of mystique, but diving on an historical shipwreck is even more thrilling and definitely more challenging. These shipwrecks are fragile time capsules containing important information about a bygone era and the information they contain can be easily destroyed by careless excavation. Some divers only value the cargo but the real treasure is the whole ship: its structure, cargo and the historical context.

Studying each shipwreck from this perspective means that everything onboard is valuable in determining the date and origin of the vessel. The remains of perishable items onboard at the time of sinking, as well as the vessel’s design and construction method, are just as crucial as the cargo when it comes to fully understanding the importance of the wreck site.

By applying the same fastidious methods of excavation to each of the ten shipwrecks found in the South China Sea, I have been able to plot a proposed chronology for the development of ceramics. This wouldn’t have been as clear or comprehensive, if ten different people using different research criteria and techniques had undertaken the excavations.

Examining each ship’s cargo provided a lot of information. Most ships were loaded with items from different countries of origin, which not only sheds light on the trading routes, but also provides important information about the range of contemporaneous forms and styles of trade goods that were available along the route. Recording where each artefact was located often helps to unravel the true circumstances surrounding the item. For example, on one occasion we found a few pieces of pottery that were older than the rest of the cargo, which possibly indicates the existence of a small trade in antiques at that particular time. However as these pieces were discovered in a different location from the main cargo, it’s more likely to assume they were intended as gifts or were part of the personal effects of someone onboard.

By examining the remains of the ship it’s possible to determine its design, construction method and the type of timber used. This information can tell much about the spread of shipbuilding techniques throughout the region. A further examination of the ship’s loading arrangement and other objects found onboard provide a rather good picture of the historical events preceding the ship’s sinking. It’s only when we combine all these factors that we can fully understand a shipwreck site.

Excavating historical shipwrecks is a daunting and painstaking business requiring enormous patience and stamina. I couldn’t wait to get started.

Even though today’s ships are strongly built, carry good navigational equipment and charts and are manned by highly trained officers, an average of two ships per day still end up on the seabed - a staggering statistic!

Without any of this modern equipment and knowledge to rely on, ancient ships sailed virtually blind. Some, like Heng Tai’s ship, were also weakened through lack of proper maintenance and some were in the hands of inexperienced officers, who were not always aware of all the navigational hazards they needed to avoid. On top of this, these old ships were often terribly over crowded.

A common rule of trade was that individual merchants had to live above the compartment they had hired for their cargo. Consequently, there were a lot of passengers onboard and decks were often so crowded that people had to lie down to sleep in shifts. Water jars, and other smaller items of cargo, were stored on deck too, which made it almost impossible for the crew to respond quickly in an emergency. Presumably this would have been one of the reasons why Heng Tai’s crew couldn’t get their sails down fast enough to save the ship. Another negative effect of this overcrowding was the fire risk created by the numerous cooking fires on deck. Some of these old ships carried saltpetre and gunpowder so any fire onboard was potentially explosive.

The South China Sea offered plenty of hiding places for pirates and over the years these brigands became familiar with the course and destination of various trading ships and would lie in ambush along the route. Normally the pirates stripped the ship of its precious cargo, firearms, cannons and anchors before killing everyone onboard and setting the ship ablaze. Destroying all evidence of the ship meant they could avoid detection. Surprisingly, the ship’s iron fittings were amongst the most valuable items onboard. Iron was very scarce in Southeast Asia, during this period, which is presumably why their shipbuilders didn’t use iron nails.

The European era adversely affected the safety of shipping in the South China Sea as the Portuguese, Dutch, English, and Spanish tried their best to minimize competition by inflicting as much damage as possible on each other’s vessels as well as any other Asian ship they encountered. Numerous reports exist about Portuguese captains beaching their own ships and setting them on fire rather than letting the Dutch capture them. Yet other reports describe how the Dutch immobilised ‘unfriendly’ ships by shooting down their masts. Then the cargo, anchors and bronze cannons were looted before the ship was set ablaze. Many later blew up ‘like thunder’ after the fire had spread to the powder store.

The Chinese and hybrid Southeast Asian vessels were better at surviving storms and reefs than any other local type of ship. Their transverse bulkheads divided the ship into watertight compartments that could stay afloat if one or two of them became flooded. They would simply jettison the cargo from the damaged compartments, repair the broken structure from inside and then continue sailing. All Chinese ships had bulkheads that went all the way to the deck and were quite watertight. Watertight transverse bulkheads are still employed by ship designers today, which shows how innovative these early Chinese craftsmen had been. The Titanic sank because her watertight bulkheads didn’t go all the way to the upper deck and water was able to flow from one compartment to the other.

When a ship did sink it would have been almost inevitable that everyone onboard perished. The chance of survival depended on how far the ship was from shore when it sank. Of the ten historic wrecks excavated in the South China Sea, there’s only three (the Desaru, Tanjung Simpang and Wanli) that were close enough to shore for survival to have been possible. Sadly, most people onboard would have died and there would be no record of them. The human cost this early trade exacted is something I’m always respectfully mindful of when we work on a site. Thankfully it’s very rare to find human remains on these sites. Most of the passengers and crew would have jumped overboard before the ship sank and would have been swept away on the current.

I was intrigued to discover that there were several Thai laws that related specifically to sailors even though there are no records of a strong maritime tradition. One law from 1350 prohibits the wife of a shipwrecked sailor from remarrying for seven years after his departure. This seems to have been quite a sensible law when you consider how long it might take for a shipwrecked survivor to eventually make his way back home. In 1690 a German traveller boarded a Dutch ship in Batavia that was heading first to Thailand and then onto Japan. Onboard he met a Japanese passenger who was finally going home after being shipwrecked in the South China Sea 10 years earlier. He and a few other survivors had been washed onto on a small sandbank in the middle of the South China Sea where they lived for a few years before being spotted and rescued. The sandbank offered little in terms of quality of life being only fifty-three paces long and twenty-four paces wide! When he finally returned to Japan, he found his wife had remarried and produced a son.

The same law states that a sailor has the right to give evidence in court in the furtherance of settling disputes involving other sailors. The fact that these laws had already been formulated by 1350 indicates that there was already a thriving Chinese seafaring community in Thailand before the ‘Ming ban’ of 1371. It also adds weight to my theory that part of the Chinese migration of Cizhou potters started as early as 1280 when the Mongols invaded China and established the Yuan dynasty. These early immigrants most likely started the production of underglaze painted ceramics at Sukhothai, almost a hundred years before celadon production got underway at the Sisatchanalai kilns. This theory is supported by evidence gathered from the Cizhou kiln sites and the Turiang shipwreck. This shipwreck cargo also reversed the earlier belief that Sisatchanalai was the first Thai kiln in export production.

The 15th century Melaka Maritime Code specifies rules pertaining to merchants and provides a general guide for ships as well as trading procedures. In this, the earliest known maritime code, it states that neither the merchant or the captain are liable to the owner for any lost goods if the cargo had to be jettisoned (a common practice if the ship hit a reef and needed repairs) or was totally lost by shipwrecking. One can only assume that ships must have been lost quite frequently otherwise there would be no need for such a law.

Before sipwrecks were discovered there was little archaeological evidence available to help art historians date ancient pottery. They theorised about origin, style of painting and choice of motifs, the kind of oxides used in the decorations and, in some cases, the density of the colour. They also considered the type of clay used to mould the pot and the techniques involved in making the pottery. But without a reference point much of this was educated guesswork mostly based on museum collections of unproven origin. It was even thought that finer and more detailed decorations belonged to an earlier period and that somehow the art of decorating pots had devolved over time and become less refined

The problem with this early method of dating is that it places too much emphasis on separating the different types of pottery into narrow time periods. This has led to pieces that were actually made at the same time and place being given different dates. Experts rarely considered the possibility that these different styles were produced contemporaneously. There was also little appreciation of the fact that not all of the potters and decorators would be equally skilled and that therefore some pots would look artistically superior to others. In addition, these criteria were often applied to pieces in museum collections from unknown origins and so the research didn’t contribute to a long lasting chronology of ceramic ware.

It’s in this area that historical shipwrecks have provided valuable new insights. Most of the cargoes we’ve examined contained an array of pots, which according to the old way of dating, would have been made many years apart. But in fact most, if not all, of the objects found onboard these historic wrecks have revealed that a greater variety of ware was available than had previously been expected. It also seems clear that the production of different forms and styles of decoration overlapped and that each type was manufactured over a longer period than previously thought. The contribution these shipwreck cargoes have made to the dating of ancient ceramics is one of the most important things to have come from their discovery and excavation.